The invention relates generally to heat radiant or reflector devices composed of ceramic or cement materials for use in cooking grills burning liquid fuel. More particularly, the invention relates to such devices comprising a cylindrical radiator member suspended above the burner flames of the cooking grill.
Cooking grills using liquified or compressed gases as fuel, such as propane, are well known. Industrial models are used in restaurants and portable units are used at home by many individuals. In general, the gas grills comprise an elongated burner element or elements, typically either straight, U-shaped or H-shaped, mounted horizontally and having a plurality of apertures along its side perimeters which allow the gas to escape in a controlled manner to be ignited. The flames supply the heat to cook food placed on a grate or grill positioned above the burner elements. The burner element apertures are spaced to produce an even heat distribution to the grill.
Problems associated with this type of cooking grill include the fact that the aperture spacing is not sufficient by itself to insure optimum heat distribution. The areas directly above the flames are hotter than areas between the flames. Additionally, much heat is lost without beneficial effect, since the region of highest temperature is directly vertical from the flame center with rapid drop in temperature as the distance from this line is increased. Various radiants or heat radiators, usually composed of a metal material, are used in an attempt to solve this problem. These are typically shaped to have a flat bottom panel and one or two planer flanges angled upward from the side or side of the bottom panel. The radiant is mounted directly above the flames of the burner element, causing the flame itself and the heat to be diverted from the vertical path. Problems associated with these radiant devices are that there is rather rapid deterioration from the direct contact of the flames on the metal surfaces, the heat is still not ideally distributed and the surfaces act as traps for grease dropping from the food being cooked on the grill, which requires either frequent cleaning or results in flare-ups which can char the food. Another attempted solution to the problem of uneven heat distribution is through the use of diffuser stones, usually composed of pumice rock, held on a second grate. This solution does not optimally distribute the heat as the rocks are randomly distributed and also suffers from the grease flare-up problem.
The invention described herein is a novel radiant structure, both in configuration and material composition, resulting in an improved gas cooking grill. The radiant is preferably composed of a cement-type combination of crushed pumice and calcium aluminate for high heat reflection properties. The main radiant element is circular in cross-section and is mounted horizontally above the burner elements. The shape of the radiant corresponds to the particular burner shape--either straight, U-shaped or H-shaped. This cylindrical configuration better distributes the heat from the burner flames and does not retain any grease dropping from the food, and the material composition is more highly heat reflective and more degradation resistant than metal. Preferably, a flat reflector panel of the same composition is also positioned below the burner elements to return any heat directed downward from the cylindrical radiant.
It is an object of this invention to provide radiant for use in gas cooking grills which is more heat reflective, more degradation resistant, better distributes the reflected heat and does not retain grease during the cooking process.
It is a further object to provide such a radiant composed of a ceramic or cement-type composition, and more particularly composed of a combination of crushed pumice and a refractory additive, such as calcium aluminate.